blundar

You may or may not know, several of us have been collaborating with the final goal of a free. open-source like modified honda ECU supporting boost, vtec, n2o/external relay control, datalogging and pretty much anything else people want. Over the next week or two, I am going to try to add a hackedup WebCVS system and other tools to make collaborative work easier. Collaborative commenting of code dumps, group examination of new subroutines and sharing of ideas should be easier with the new system. Above all, FREE and OPEN exchange of information is encouraged. If the idea of hacking away in the ECU appeals to you, but you are intimidated by it, don't give up. Many of the valuable contributors to the site had little/no microcontroller experience prior to the pgmfi project.

The current consensus is that OBDII is not worth attacking at this time.

So far most work has focused on the 91 CRX Si PM6. Fuel and timing control routines have been isolated and commented. Support for custom fuel and timing maps has been made simple by a series of excel spreadsheets that automaticallyh convert between real world units and hex values to input into tables. Recurving tables for bigger injectors is easy. Datalogging and larger fuel tables to support boost are both in an alpha stage of development. A sound strategy for a 1wire vtec system has been suggested, although no code has been written. Testers and coders are desperately needed.

OBD1 ECUs are considerably harder to understand than OBD0. The microcontroller used does not have any FREE development tools unlike the OBD0 ecus. Glenn Anderson, who aparently wrote the first disassembler for Hondata based on some 66K manuals Doug Macmillan acquired, was kind enough to provide a mostly disassembled, partially commented PW0 dump. Additionally, many of the contributed rom images have been analyzed to determine the size and shape of fuel/timing tables. Current projects are basically writing a assembler and disassembler for the architecture so that further work can be done.

Sorry for the long post here, but I sincerely believe that understanding the Honda computers to the point where they can be used purely as a hardware platform for whatever software routines people care to write is not an unreachable goal. No one seems to be able to devote themselves to this project as their dayjob, so the "two heads are better than one" approach seems to be the only way forwards. Even if you just come and leech some of the many uploaded stock and aftermarket roms, spread awareness of the site.

http://pgmfi.crx-forum.org

Thanks
-D

DigitalFusion

i think you would prolly have a lot more people interested if u didnt limit it to OBD0's. OBD1 would be a better place to start considering there are a lof of people running those vs OBD0

blundar

We haven't limited ourselves to OBD0!!!
The OBD1 project is just somewhat trickier and has not progressed as far yet. If anything, the OBD1 guys need MORE help than the OBD0 guys!

ion_four

Okay, I've got OBD1, but I want to help. I don't know much about programming or electronics, but a little, little bit of both. I think some other people should get involved too. I'm sure there are a ton of people on here that code and hack ****. I've been toying with some simple circuits such as limiting the MAP sensor and tuning the signal down for larger injectors, but neither is very efficient, so this is the way to go.
What're some good resources to learn about PICs/microcontrollers and whatnot?


[Modified by ion_four, 10:24 PM 6/28/2002]

legendboy

Honda+Linux=hondix

falcongsr

linux + Honda = Linda.

blundar

I'm actually in the middle of adding the oki 66K series (OBDI, II) to GNU GAS to be the ASM/DASM of the project....
Wish me luck.
I do most of my dev work under linux.

MarsGodofWar

http://www.bgsoflex.com/megasquirt.html

While not a "hacked" Honda ECU, it is cheap (~$120) and I just so happen to have one running my '95 hatch at this very moment. The only big thing left to do is get better curves for the Honda temp sensors; right now i'm using values out of my Helms which are off by as much as 40 degrees at times. I plan on working on that tomorrow.

I'd be happy to answer any questions,

David



[Modified by MarsGodofWar, 3:32 AM 6/29/2002]

eddie1681

[Modified by b20z, 4:57 AM 6/29/2002]

Full-Race Geoff

hell yeah!! nice job with that. I was going to put haltech f9 on my baja prerunner piece of **** truck project but ive been thinking about doing this and sticking with the stock vaccuum advance distributor, while using gm sensors.

I assume you are just using this to control fuel? Im interested to hear how it works! It looks no harder to assemble than a tech-edge DIY Wideband o2 controller so that is pretty appealing... im glad to see someone has tackled this! props go out to ya!

MarsGodofWar

First off, its not MY design. Bruce Bowling and Al Grippo did the first design and released it to the world and I got in on the first group buy they did. As people began installing them and problems popped up and were solved, some (small) modifications were made and now they are having a second group buy for the V2.2 board.

It is right now only a fuel controller. However, the V2.2 board has a header on it that allows other boards using the same micro-controller to be connected to the fuel controller. A group member has done a preliminary prototype of a spark controller that will work in conjection with the fuel controller. Bruce and Al plan on continueing work on their own spark controller as soon as the second group buy is over.

There is ALOT of good info on the yahoo groups (megasquirt and megajolt). Not alot about hondas on there cause AFAIK i'm the only guy running one on a honda.

The great thing about it is that it is an open source type project. The code is all there if you want to add a functionallity that is missing for your project. For instance one of the group memebers is working on a type of staged nitrous control code mod which i think will work quite nicely for VTEC withjust a bit more work(I'm waiting impatiently for him to release his code). People also have plans for boost control and auto-tune functionallity with a WBO2(it currently can run with a WBO2).

David

PS: Maybe someone can help me out with some info. I've been trying to find out what kind of sensors are in the distributors of OBDI hondas? Is the Cam Position Sensor a 60-1 type arrangement or what?

PPS: I know there is a guy who has a sandrail running with a toyota motor and i *think* its a truck motor but i'm not sure.




[Modified by MarsGodofWar, 2:41 PM 6/29/2002]

HXMan

I myself would like to see the OBD2 ECU hacked....

falcongsr

OBD2 focuses on emissions more than power. its a bad place to start for performance. better to drop in a different CPU like OBD1, AEM, or one of these nifty homemade jobs.

i wish i had time to support an effort like this, but my time is occupied with integrating a processor into a differnt kind of machine altogether...

blundar

Ok... Many things:

1. The megasquirt is seriously cool. Adding spark control would rock. Adding external relay control would rock.

2. The HF ECUs are tuned factory for fuel economy, yet they serve as the basis for the zdyne 1wire vtec! The argument that OBDII is more about economy is not a valid one in my mind. I see no reason for an OBDII setup to not be just as fast as an OBDI setup. Just cause you have 60 zillion sensors doesnt mean you need to use them.

3. The process of writing a 66K DASM is going slow. Much luck needed

falcongsr

i was saying the software algorithm on the obd2 processors is not designed for power, but for effeciency. sorry. er um i am drunk nevermind.